In many materials, you may want to combine multiple normal maps to add complexity and detail. For example, you could have a tile pattern as your base and additional scratches or decal details on top. Blender doesn’t have a one-click solution for this, but with some node work, you can seamlessly blend multiple normal maps. In this tutorial, I’ll show you a method that separates, combines, and normalizes normal map channels for a clean, controllable result.
Step 1: Set Up Your Material
1. Open the shader editor
2. Make a new material
3. Go into material preview using the Z-key
3. Drag-and-drop your texture maps into the shader editor
| Texture maps are two-dimensional image files applied to the surface of a 3D model to define its visual properties and surface details |
4. Connect the base color (or albedo) to the base color input of the principled shader
| An albedo map (also known as a base color map) is a 2D texture that defines the pure, intrinsic color of a surface material without any baked-in lighting, shadows, highlights, or reflections. |
| The Principled BSDF (Bidirectional Scattering Distribution Function) node is the default, all-in-one surface shader in Blender 3D, designed to simplify the creation of realistic materials by combining multiple shading layers into a single interface. |
5. Connect the roughness to the roughness input of the principled shader and change the color space to non-color
| A roughness map is a grayscale texture used in Physically Based Rendering (PBR) to define the microsurface variations of a material, determining how light scatters or reflects off its surface. |
6. Set both normal maps’ color space to Non-Color Data in the image texture node settings
| A normal map is a texture mapping technique in 3D computer graphics that simulates the illusion of surface depth, bumps, and dents without altering the actual geometry of a 3D model. |
7. Normal maps are made up of an RGB spectrum where red represents the X-axis, green represents the Y-axis, and blue represents the Z-axis
Step 2: Separate RGB Channels
1. We need to separate these values by using SHIFT + A to add a Separate Color node
| The Separate Color node in Blender splits an input image or color vector into its composite color channels, with the specific outputs determined by the Mode property. |
2. Duplicate this node using SHIFT + D
3. Connect each normal map to its own Separate RGB node
| The Mix Color node (formerly the Mix RGB node) in Blender mixes two input values—such as colors, vectors, or floats—using a Factor to control the amount of interpolation. |
4. This separates the red, green, and blue channels of each normal map for independent blending
Step 3: Combine the Channels with Add
1. Use SHIFT + A to add a mix color node and change the blending mode to add
2. Make two duplicates of the mix color node
3. Connect the red output of the separate color nodes to the first mix color node
4. Connect the green output of the separate color nodes to the second mix color node
5. Connect the blue output of the separate color nodes to the third mix color node
Step 4: Recombine the Channels
1. Use SHIFT + A to add a combine color node
| The Combine Color Node is a converter node in Blender used to reassemble separate color channels (such as Red, Green, Blue, and Alpha) back into a single combined color value. |
2. Connect the first mix color node to the red input of the combine color node
3. Connect the second mix color node to the green input of the combine color node
4. Connect the third mix color node to the blue input of the combine color node
5. This recombines your separated channels into a single RGB output
Step 5: Normalize the Result
1. Use SHIFT + A to add a Vector Math node
| The Vector Math node in Blender performs selected mathematical operations on input vectors, with dynamic inputs and outputs that adapt to the chosen operator. |
2. Change the operation to normalize
| In Blender’s Vector Math node, the Normalize operation scales the magnitude (length) of the input vector to exactly 1 while keeping its original direction intact. This process creates a unit vector, which is essential for operations where only direction matters, such as calculating surface normals or determining angles via the dot product. |
3. Connect the output of the combine color node to the vector input of the vector math node
4. Normalizing ensures that the combined normal map has proper direction and intensity without one map overpowering the other
Step 6: Apply the Normal Map
1. Use SHIFT + A to add a normal map node
| The Normal Map node in Blender generates a perturbed normal vector from an RGB normal map image, which is typically chained with an Image Texture node in the color input. |
2. Connect the output of the normalize node to the color input of the normal map node
3. Connect the normal map node to the normal input of the principled shader
4. Adjust the strength parameter of the normal map node to control the overall intensity
Step 7: Node Group
1. Select the 8 nodes that make up the blending of the normal maps
2. Use CTRL + G to group them together
3. Use the N-key to open the side panel and rename the group
4. Using the TAB key will bring you back to your shader editor
Conclusion
By separating, adding, recombining, and normalizing normal map channels, you can combine multiple details without one overriding the other. This method works great for adding scratches, decals, or layered surface detail on top of your base textures. Once you understand this workflow, it opens up endless possibilities for richer, more complex materials in Blender.